1. Field of the Invention
The present invention relates to a pool water purifying device and, more particularly, to a pool water purifying device for purifying water in a cultivation pool or scenic pool.
2. Description of the Related Art
The main pollutants to water in a cultivation pool or scenic pool mainly come from dust, fallen leaves, and nitrogen-containing organic substances, such as feces of aquatic creatures and residuary foods for the aquatic creatures. After decomposition of the nitrogen-containing organic substances by microorganisms, inorganic nitrides (such as ammonia nitrogen and nitrate nitrogen) accumulate in the pool water and cause eutrophication of the pool water, greatly affecting the ecology of the pool. For a cultivation pool, the aquatic animals could even be poisoned if the concentration of ammonia nitrogen is too high, leading to mass deaths of the aquatic animals and reducing the cultivating yield. Thus, ammonia nitrogen in the pool water must be removed.
In current techniques, a water wheel is used to continuously agitate the water level to increase the dissolved oxygen, turning ammonia nitrogen into less toxic nitrate nitrogen through nitrification. However, high-concentration nitrate nitrogen greatly helps propagation of algae, and excessive algae often causes degradation of water or even deaths of aquatic animals. Thus, cultivators have to use chemicals to control the water quality, which increases the yield at the cost of reduced quality of aquatic animals and reduced market prices.
In other techniques, probiotics are cast into the pool water to nitrify and denitrify inorganic nitrides (such as ammonia nitrogen and nitrate nitrogen) by microorganisms such as nitrosomonas, nitrobacteria, and denitrifying bacteria. Although this method is more natural, it has a slow reaction speed resulting in poor efficiency, is apt to be restricted by weather conditions, and is only suitable for treating water having a low concentration of ammonia nitrogen. Furthermore, the purchasing cost of probiotics is high, and additional nutrient salts must be added into the water when the nutrient salts for treating the bacteria in the water are insufficient, leading to a burden to the costs.
Furthermore, in addition to removal of ammonia nitrogen, purification of the pool water also requires filtration of impurities and disinfection to maintain the water quality of the pool water. Furthermore, water temperature modulation is preferably provided when the water temperature is too high or too low. However, the devices for removing inorganic nitrides from pool water, for filtering impurities, for disinfection, and for modulating water temperatures are separate from each other, such that the water purifying procedures must be carried out one by one. Furthermore, the operational sequence of the devices with different functions must be operated and adjusted by human labor rather than automatic, continuous operation. The water purifying efficiency is poor, and the water purifying effect could be adversely affected due to improper operation of the operational sequence. Furthermore, the devices with different functions occupy considerable space for storage, leading to troubles in the space management of the operating environment.